I have read reference on this forum and others about using diesel oil as an engine cleaner. It has been stated that this is preferable than some of the additives which clean too well. My challenge, that I am sure forum gurus can help with, is I am great at following step by step instructions but have not been able to find more than a passing reference to the process in a number of different forum postings. If someone wants to use diesel oil as an engine cleaner what would the step-by-step instructions be?

Thanks in advance

Take a quart of oil out of the crankcase and refill with a quart of kerosene.  Place bike on center stand and run for about 30 minutes. vary the throttle setting during that period.  Don't go for a ride with this mixture, just let it run.  Drain. Replace filter and fill with what ever oil make you happy.  Ride. 


What are you riding and how many miles/kilometers are on the machine?

I've read where automatic transmission fluid is a good engine oil flush fluid. I think it's better than kerosene.


Drain the oil and replace the filter, fill with ATF and run the engine, but don't ride. Then replace oil and filter.

I've noticed some variation on the technique.

Regards

Diesel is too harsh; sidestep that one. Not a safe solvent/lubrication ratio. 

Add one quart of ATF to your crankcase when you've got room for it. Start your engine, let it idle periodically mildly revving it. Do this for about 10 minutes, let it cool 'nuff to drain it. 

Replace filter (and crush washer), fill with your preferred oil (another argument waiting to happen) and go about your biz. 

ATF will clean the engine upper end (or side end in this case) and maintain a safe level of lubrication in the process. Do this about every third oil/filter change and you're engine will run smoother, quieter and cleaner.

Kerosene is abrasive and should not be used in flushing an engine.
Use a diesel oil that is for light diesels as found in modern cars and not the oil used in the big diesel like truck or marine engines.
I don't use anything but Shell Helix RX5 and have found it quite satisfactory in any of my engines and as far as I know the reason for using the diesel oil is to clean the sprag clutch for the starter.  I have never had a problem with the starter clutch so have never had reason to consider using anything else.

JAOT.  (Just another oil thread.)  

RicK G wrote:Kerosene is abrasive and should not be used in flushing an engine.
Use a diesel oil that is for light diesels as found in modern cars and not the oil used in the big diesel like truck or marine engines.
I don't use anything but Shell Helix RX5 and have found it quite satisfactory in any of my engines and as far as I know the reason for using the diesel oil is to clean the sprag clutch for the starter.  I have never had a problem with the starter clutch so have never had reason to consider using anything else.

Rick,

You have hit the nail on the head. The starter is spinning and but the starter clutch is not engaging recently. Not all the time but certainly when the engine is cold. I had thought a diesel oil clean might solve that, along with a gentle cleaning of the rest of the crankcase. Now how to proceed?

Just treat it like a regular oil change at 5000k intervals or whatever you have chosen.

RicK G wrote:Just treat it like a regular oil change at 5000k intervals or whatever you have chosen.

I have seen some people quote leaving for between 100 and 500 miles. Reuse the filter and then replace filter when putting regular oil back in. Others have used new filter with diesel oil and another new filter when changing back to regular oil. Hence my confusion.

Paul Glaves, former BMW wrench and a "guru" of sorts when it comes to classic Ks, recommends either Rislone or CD-2 for a few hundred miles, followed by a filter and oil change of course, to address the starter sprag issue.

Article you might find interesting: http://bmwmotorcycletech.info/kstartersprag.htm

duck wrote:Paul Glaves, former BMW wrench and a "guru" of sorts when it comes to classic Ks, recommends either Rislone or CD-2 for a few hundred miles, followed by a filter and oil change of course, to address the starter sprag issue.

Article you might find interesting: http://bmwmotorcycletech.info/kstartersprag.htm

Thanks Duck.

duck wrote:Paul Glaves, former BMW wrench and a "guru" of sorts when it comes to classic Ks, recommends either Rislone or CD-2 for a few hundred miles, followed by a filter and oil change of course, to address the starter sprag issue.

Article you might find interesting: http://bmwmotorcycletech.info/kstartersprag.htm

Thanks Duck. The problem as described is exactly what I am experiencing. Will follow his advice.